RSX utility for converting Logical Block order virtual RX50 disks to Track, Sector order.

   Several posts back. I posted a utility, TSTOLBN, that converts RX50 disk images that are in the same layout as a physical RX50 diskette (I call that Track, Sector or TS  order - it  has the blocks in a track  interleaved every other block, and the track  starting sector  is skewed by two sectors/each track, plus the last track is at the first physical track on the disk) , into just a string of blocks, in numerical order - the format used by RSX and VMS virtual disks, and SIMH disks (I call that Logical Block order, LBN). 

  That does the business for all of my needs - I use RX50 images as files on P/OS, RSX, VMS and SIMH, and they all need LBN format. Additionally, if you have an LBN order virtual disk, you can read and write it directly ro a real RX50 diskette, and the MSCP/Pro Controller will take care of converting it to/from the physical Track Sector format on the disk for you. But I've been noticing of late that people are needing RX50 images that they can use in assorted external disk emulating gizmos - and they all required the same format as a physical RX50 uses - TS order.

  Several folks have written converters in C and Python to convert LBN to TS order. But I prefer to work in the DEC environment as much as possible, so I needed a tool to do this conversion, that runs purely in the RSX and P/OS environment, no Windows/Linux/Python/C compiler required.

  So I took a little time and, using the previous converter (TSTOLBN, Track Sector To LBN) as a base, created a utility called LBNTOTS (Logical Block To Track Sector).

  Really, it's almost the same program - just had to make a few changes to the interleave and sector translation arrays, and the funny first track/last track logic. And I cleaned it up a little in general. 

  Here's the source code...

lbntots.mac

To make...
 >mac lbntots=lbntots
 >tkb
 TKB>lbntots=lbntots
 TKB>/
 Enter Options:
 TASK=...LTT                   ;stands for LBN To TS
 LIBR=FCSRES:RO       ;this is optional - saves memory on a busy system
 //
>

 To use...
 >run lbntots
 LTT>outfile=infile

 or install it and use direct from the command line

 >ins lbntots
 >LTT outfile=infile

 Outfile extension defaults to .dsk, infile extension to .dsk

Install prorgams via ethernet without OS - update to PDP11 version

  So my 11/73 system, in a BA23, has recently developed a memory problem and won't boot. The ROM diags show...

Expected data   = 052525
Bad data            = 052524
Address             = 02740032

 Looks like one bad bit on a chip. I replaced the card with a spare card, but it's too small and now RSX can't boot, I want to run some memory diags on the failed card, hoping that they will be able to give me some more clues as to which chip has carked it.

  My XXDP RX50 only had disk diags on it, so I needed to add QBUS memory diags, VSMAC0 and VMJAB0 (sometimes listed as CVMSAC0 and CVMJAB0).

  I used SIMH and an RL02 XXDP disk image to create a new XXDP RX50 disk image, comtaining the memory diags and the oft used ZRCHB0, the MFM disk formatter. Next I needed to copy the RX50 image to a physical floppy.

  I have a set of tools for this - the client/server disk copying tools I wrote to load VMS and RSX on systems without OSes. They should work fine on an RX50, since they are controlled by an RQDX3. 

  I had a look at them, and relaized that the VAX server tool, LOCALWRITE, had been upgraded a while back, and the PDP11 client tool, REMWRT, was no longer compatible with it. LOCALWRITE and REMOTEWRITE had been updated to allow entering what unit number to write to, and what file to download (per suggestions and help from Hans-Ulrich Hölscher), as well as some changes to the communiction protocol used between them. (When copying to a PDP11, the VAX LOCALWRITE server is used, since I haven't written LCLWRT yet, a PDP11 version of the server task).

  So I prodced a new version of REMWRT with the needed changes. They aren't interesting enough to describe. Here's the new version of REMWRT.MAC

remwrt.mac

  Please see earlier blog post for the instructions about how to assemble, link, load and use it.

 So, I used LOCALWRITE and REMWRT to copy the XXDP RX50 image to a real RX50 on the system in question. Copy worked fine, disk boots OK. Next step - take out the spare memory card and reinsert the bad one, and boot XDP and run the diags. Here's hoping for some useful info....